On Laterally Perturbed Human Stance: Experiment, Model, and Control

Figure 6

(a) Experiment trajectory in blue, “no control” (I) in red, and PD control (IIa) in dashed red. (b) Experiment trajectory in blue and PD control with 20 ms delay (IIb) in dashed red. First plot is the ankle trajectory, second is the hip, and third is the perturbation. While with no control applied, the system obviously collapses, also simple PD control, while being able to stabilize was not able to match the angular trajectories of the experiment. If a delay is introduced, the system becomes highly unstable. The PD controller used here is the MATLAB : Simulink build in PID controller with , , , and .

(a)

(b)